During industrial soldering, a heated solder bath is maintained and it is necessary to scrape off dross from the top of the solder bath at frequent intervals, the dross primarily being formed of oxides of tin and good solder. The generation of dross is higher in a Sn—Ag—Cu alloy (Pb-free solder) than in a Sn—Pb solder (leaded solder).
Dross collected from industrial soldering contains a good amount of usable solder and an oxidized residue, which should be disposed. However, with conventional methods of solder recovery, the oxidized residue cannot be completely removed, and the oxidized residue still contains substantial amount of solder.
A conventional method of recovering solder from dross is through heating the dross and agitating the heated dross. The solder is collected subsequently after the operator has removed the upper oxidized residue with a ladle. However, this solder recovering method, in addition to removing the oxidized residue, also collects the usable solder. Further, as the process is more or less manual, it demands high level of user skill. Still, the efficiency is not what is expected. Further there are safety concerns, as the environment in which the process is carried out is generally dusty and temperatures are significantly high to work. The operation is generally very labour-intensive. Finally, there is a significant risk of operator exposure to flux fumes, which can be toxic.
Accordingly, there is need for a method and/or a device that is not only safe to use, but also efficient in terms of the amount of solder it helps recover from the dross.